package com.lam.common.utils;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.lam.common.utils.html.EscapeUtil;

/**
 * 获取IP方法
 * 
 * @author lam
 */
public class IpUtils {
	
	private static final Logger logger = LoggerFactory.getLogger(IpUtils.class);
	
	public static final String LOCAL_HOST_IP = "127.0.0.1";

	// 未知地址
	public static final String UNKNOWN = "XX XX";
	
	public static String getIpAddr() {
    	return getIpAddr(null);
    }
		
	public static String getIpAddr(HttpServletRequest request) {
		if (request == null) {
			request = SpringUtils.getRequest();
		}
		if (request == null) {
			return "unknown";
		}
		String ip = request.getHeader("x-forwarded-for");
		if (StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("Proxy-Client-IP");
		}
		if (StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("X-Forwarded-For");
		}
		if (StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("WL-Proxy-Client-IP");
		}
		if (StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("X-Real-IP");
		}
		if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
		if (StringUtils.isEmpty(ip) || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getHeader("HTTP_X_FORWARDED_FOR");
		}
		if (StringUtils.isBlank(ip) || "unknown".equalsIgnoreCase(ip)) {
			ip = request.getRemoteAddr();
		}
		return "0:0:0:0:0:0:0:1".equals(ip) ? LOCAL_HOST_IP : EscapeUtil.clean(ip);
	}

	public static boolean internalIp(String ip) {
		byte[] addr = textToNumericFormatV4(ip);
		return internalIp(addr) || LOCAL_HOST_IP.equals(ip);
	}

	private static boolean internalIp(byte[] addr) {
		if (addr == null || addr.length < 2) {
			return true;
		}
		final byte b0 = addr[0];
		final byte b1 = addr[1];
		// 10.x.x.x/8
		final byte SECTION_1 = 0x0A;
		// 172.16.x.x/12
		final byte SECTION_2 = (byte) 0xAC;
		final byte SECTION_3 = (byte) 0x10;
		final byte SECTION_4 = (byte) 0x1F;
		// 192.168.x.x/16
		final byte SECTION_5 = (byte) 0xC0;
		final byte SECTION_6 = (byte) 0xA8;
		switch (b0) {
		case SECTION_1:
			return true;
		case SECTION_2:
			return b1 >= SECTION_3 && b1 <= SECTION_4;
		case SECTION_5:
			return b1 == SECTION_6;
		default:
			return false;
		}
	}

	/**
	 * 将IPv4地址转换成字节
	 * 
	 * @param text IPv4地址
	 * @return byte 字节
	 */
	public static byte[] textToNumericFormatV4(String ipStr) {
		if (StringUtils.isBlank(ipStr)) {
			return null;
		}

		byte[] bytes = new byte[4];
		String[] elements = ipStr.split("\\.", -1);
		try {
			long l;
			int i;
			switch (elements.length) {
			case 1:
				l = Long.parseLong(elements[0]);
				if (l < 0L || l > 4294967295L) {
					return null;
				}
				bytes[0] = (byte) (int) (l >> 24 & 0xFF);
				bytes[1] = (byte) (int) ((l & 0xFFFFFF) >> 16 & 0xFF);
				bytes[2] = (byte) (int) ((l & 0xFFFF) >> 8 & 0xFF);
				bytes[3] = (byte) (int) (l & 0xFF);
				break;
			case 2:
				l = Integer.parseInt(elements[0]);
				if (l < 0L || l > 255L) {
					return null;
				}
				bytes[0] = (byte) (int) (l & 0xFF);
				l = Integer.parseInt(elements[1]);
				if (l < 0L || l > 16777215L) {
					return null;
				}
				bytes[1] = (byte) (int) (l >> 16 & 0xFF);
				bytes[2] = (byte) (int) ((l & 0xFFFF) >> 8 & 0xFF);
				bytes[3] = (byte) (int) (l & 0xFF);
				break;
			case 3:
				for (i = 0; i < 2; ++i) {
					l = Integer.parseInt(elements[i]);
					if (l < 0L || l > 255L) {
						return null;
					}
					bytes[i] = (byte) (int) (l & 0xFF);
				}
				l = Integer.parseInt(elements[2]);
				if ((l < 0L) || (l > 65535L)) {
					return null;
				}
				bytes[2] = (byte) (int) (l >> 8 & 0xFF);
				bytes[3] = (byte) (int) (l & 0xFF);
				break;
			case 4:
				for (i = 0; i < 4; ++i) {
					l = Integer.parseInt(elements[i]);
					if (l < 0L || l > 255L) {
						return null;
					}
					bytes[i] = (byte) (int) (l & 0xFF);
				}
				break;
			default:
				return null;
			}
		} catch (NumberFormatException e) {
			return null;
		}
		return bytes;
	}
	
	public static String getHostIp() {
		return getHostIp(false);
	}

	public static String getHostIp(boolean getActual) {
		try {
			if(getActual) {
				return InetAddress.getLocalHost().getHostAddress();
			}
			
			List<String> ipList = getHostByDomain("localip");
			if(CollectionUtil.isNotEmpty(ipList)) {
				return ipList.get(0);
			}
			return InetAddress.getLocalHost().getHostAddress();
		} catch (UnknownHostException e) {
			logger.error("获取当前ip异常", e);
			throw new RuntimeException("获取当前服务器ip失败");
		}
	}

	public static String getHostName() {
		try {
			return InetAddress.getLocalHost().getHostName();
		} catch (UnknownHostException e) {
			logger.error("获取当前HostName异常", e);
			return "UnknownHostName";
		}
	}
	
	public static List<String> getHostByDomain(String domain){
		
		List<String> hostList = new ArrayList<>();
		try {
			InetAddress[] addresses = InetAddress.getAllByName(domain);
			for (InetAddress address : addresses) {
				hostList.add(address.getHostAddress());
			}
		} catch (UnknownHostException e) {
			logger.error("根据域名获取Host异常", e);
			//hostList.add(domain);
		}
		return hostList;
	}
}